Editing Precautionary principle (section)

==Application==
Various interests being represented by various groups proposing the principle resulted in great variability of its formulation: one study identified 14 different formulations of the principle in treaties and non-treaty declarations.<ref>{{Cite journal|last2=Vecchia|first2=Paolo|last3=Repacholi|first3=Michael H.|date=12 May 2000|title=Science and the Precautionary Principle|journal=Science|volume=288|issue=5468|pages=979–981|doi=10.1126/science.288.5468.979|issn=0036-8075|pmid=10841718|last1=Foster|first1=Kenneth R.|s2cid=153469283}}</ref> R.B. Stewart (2002)<ref>{{cite journal |author=Stewart, R.B. |title=Environmental Regulatory Decision Making Under Uncertainty |journal=Research in Law and Economics |volume=20 |page=76 |year=2002 }}</ref> reduced the precautionary principle to four basic versions:
* Scientific uncertainty should not automatically preclude regulation of activities that pose a potential risk of significant harm (''non-preclusion'').
* Regulatory controls should incorporate a margin of safety; activities should be limited below the level at which no adverse effect has been observed or predicted (''margin of safety'').
* Activities that present an uncertain potential for significant harm should be subject to best technology available requirements to minimize the risk of harm unless the proponent of the activity shows that they present no appreciable risk of harm (''BAT'').
* Activities that present an uncertain potential for significant harm should be prohibited unless the proponent of the activity shows that it presents no appreciable risk of harm (''prohibitory'').

[[Carolyn Raffensperger]] of the Wingspread convention placed the principle in opposition to approaches based on [[risk management]] and [[Cost–benefit analysis|cost-benefit analysis]].<ref name=":5" /> [[David Brower|Dave Brower]] ([[Friends of the Earth]]) concluded that "all technology should be assumed guilty until proven innocent".<ref name=":5" /> [[Freeman Dyson]] described the application of precautionary principle as "deliberately one-sided", for example when used as justification to destroy genetic engineering research plantations and threaten researchers in spite of scientific evidence demonstrating lack of harm:<ref name=":5" />

{{Blockquote|text=The Precautionary Principle says that if some course of action carries even a remote chance of irreparable damage to the ecology, then you shouldn't do it, no matter how great the possible advantages of the action may be. You are not allowed to balance costs against benefits when deciding what to do.|author=Freeman Dyson|title=|source=Report from 2001 World Economic Forum}}

As noted by Rupert and O'Riordan, the challenge in application of the principle is "in making it clear that absence of certainty, or there being insufficient evidence-based analysis, were not impediments to innovation, so long as there was no reasonable likelihood of serious harm".<ref name=":4" /> Lack of this nuanced application makes the principle "self-cancelling" according to [[Stewart Brand]], because "nothing is fully established" in science, starting from the precautionary principle itself and including "gravity or Darwinian evolution". A balanced application should ensure that "precautionary measures should be" only taken "during early stages" and as "relevant scientific evidence becomes established", regulatory measures should only respond to that evidence.<ref name=":5" />

=== Strong vs. weak ===
''Strong precaution'' holds that regulation is required whenever there is a possible risk to health, safety, or the environment, even if the supporting evidence is speculative and even if the economic costs of regulation are high.<ref>{{Cite journal | last = Sachs | first = Noah M. | title = Rescuing the Strong Precautionary Principle from its Critics | journal = University of Illinois Law Review | volume = 2011 | issue = 4 | pages = 1285–1338 | year = 2011 | url = https://illinoislawreview.org/wp-content/ilr-content/articles/2011/4/Sachs.pdf | access-date = 13 October 2011 | archive-url = https://web.archive.org/web/20111028155403/http://illinoislawreview.org/wp-content/ilr-content/articles/2011/4/Sachs.pdf | archive-date = 28 October 2011 | url-status = dead }}</ref>{{rp|1295–96}} In 1982, the United Nations [[World Charter for Nature]] gave the first international recognition to the strong version of the principle, suggesting that when "potential adverse effects are not fully understood, the activities should not proceed". The widely publicised Wingspread Declaration, from a meeting of environmentalists in 1998, is another example of the strong version.<ref name="goliath.ecnext.com">{{cite journal |last1=Sunstein |first1=Cass R. |title=Does the Precautionary Principle point us in any helpful direction ? The Paralyzing Principle |journal=Regulation |date=2002 |volume=25 |issue=9 |pages=32–37 |url=https://www.cato.org/sites/cato.org/files/serials/files/regulation/2002/12/v25n4-9.pdf |s2cid=18622893 }}</ref> Strong precaution can also be termed as a "no-regrets" principle, where costs are not considered in preventative action.<ref>{{Cite book|url=https://www.scribd.com/book/195536970/The-No-Regrets-Principle|title=The No Regrets Principle by Shawn Brodof |access-date=2019-08-06 }}</ref>

''Weak precaution'' holds that lack of scientific evidence does not preclude action if damage would otherwise be serious and irreversible.<ref name="Beyond Laws of Fear">{{Cite journal | last1 = Mandel | first1 = Gregory N. | last2 = Gathii | first2 = James Thuo | title = Cost Benefit Analysis Versus the Precautionary Principle: Beyond Cass Sunstein's Laws of Fear | journal = University of Illinois Law Review | volume = 2006 | issue = 5 | pages = 1037–1079 | year = 2006 | url = https://illinoislawreview.org/wp-content/ilr-content/articles/2006/5/Mandel.pdf | access-date = 13 October 2011 | archive-url = https://web.archive.org/web/20120312021512/http://illinoislawreview.org/wp-content/ilr-content/articles/2006/5/Mandel.pdf | archive-date = 12 March 2012 | url-status = dead }}</ref>{{rp|1039}} Humans practice weak precaution every day, and often incur costs, to avoid hazards that are far from certain: we do not walk in moderately dangerous areas at night, we exercise, we buy smoke detectors, we buckle our seatbelts.<ref name="goliath.ecnext.com"/>

According to a publication by the [[New Zealand Treasury]] Department:

{{blockquote| The weak version [of the Precautionary Principle] is the least restrictive and allows preventive measures to be taken in the face of uncertainty, but does not require them (e.g., Rio Declaration 1992; United Nations Framework Convention of Climate Change 1992). To satisfy the threshold of harm, there must be some evidence relating to both the likelihood of occurrence and the severity of consequences. Some, but not all, require consideration of the costs of precautionary measures. Weak formulations do not preclude weighing benefits against the costs. Factors other than scientific uncertainty, including economic considerations, may provide legitimate grounds for postponing action. Under weak formulations, the requirement to justify the need for action (the burden of proof) generally falls on those advocating precautionary action. No mention is made of assignment of liability for environmental harm.

 Strong versions justify or require precautionary measures and some also establish liability for environmental harm, which is effectively a strong form of "polluter pays". For example, the [[Earth Charter]] states: "When knowledge is limited apply a precautionary approach ... Place the burden of proof on those who argue that a proposed activity will not cause significant harm, and make the responsible parties liable for environmental harm." Reversal of proof requires those proposing an activity to prove that the product, process or technology is sufficiently "safe" before approval is granted. Requiring proof of "no environmental harm" before any action proceeds implies the public is not prepared to accept any environmental risk, no matter what economic or social benefits may arise (Peterson, 2006). At the extreme, such a requirement could involve bans and prohibitions on entire classes of potentially threatening activities or substances (Cooney, 2005). Over time, there has been a gradual transformation of the precautionary principle from what appears in the Rio Declaration to a stronger form that arguably [by whom] acts as restraint on development in the absence of firm evidence that it will do no harm.<ref>"Precautionary Principle: Origins, definitions, and interpretations." Treasury Publication, Government of New Zealand. 2006. http://www.treasury.govt.nz/publications/research-policy/ppp/2006/06-06/05.htm</ref> }}

=== International agreements and declarations ===

===="Principle" vs. "approach"====
No introduction to the precautionary principle would be complete without brief reference to the difference between the precautionary ''principle'' and the precautionary ''approach''. Principle 15 of the Rio Declaration 1992 states that: "in order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall be not used as a reason for postponing cost-effective measures to prevent environmental degradation." As Garcia (1995) pointed out, "the wording, largely similar to that of the principle, is subtly different in that:  it recognizes that there may be differences in local capabilities to apply the approach, and it calls for cost-effectiveness in applying the approach, e.g., taking economic and social costs into account." The "approach" is generally considered a softening of the "principle":

{{blockquote|As Recuerda has noted, the distinction between the precautionary principle and a precautionary approach is diffuse and, in some contexts, controversial. In the negotiations of international declarations, the United States has opposed the use of the term ''principle'' because this term has special connotations in legal language, due to the fact that a ''principle of law'' is a source of law. This means that it is compulsory, so a court can quash or confirm a decision through the application of the precautionary principle. In this sense, the precautionary principle is not a simple idea or a desideratum but a source of law. This is the legal status of the precautionary principle in the European Union. On the other hand, an 'approach' usually does not have the same meaning, although in some particular cases an approach could be binding. A precautionary approach is a particular "lens" used to identify risk that every prudent person possesses (Recuerda, 2008)<ref>{{cite journal |author=Recuerda, M. A. |title=Dangerous interpretations of the precautionary principle and the foundational values of the European Union Food Law: Risk versus Risk |journal=Journal of Food Law & Policy |volume=4 |issue=1 |year=2008 }}</ref>}}

====European Union====
On 2 February 2000, the [[European Commission]] issued a Communication on the precautionary principle,<ref name=EU-Comm-PP/> in which it adopted a procedure for the application of this concept, but without giving a detailed definition of it. Paragraph 2 of article 191 of the [[Lisbon Treaty]] states that:

{{blockquote|Union policy on the environment shall aim at a high level of protection taking into account the diversity of situations in the various regions of the Union. It shall be based on the precautionary principle and on the principles that preventive action should be taken, that environmental damage should as a priority be rectified at source and that the polluter should pay.<ref>[http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:C:2016:202:FULL&from=EN Consolidated Version of the Treaty on the Functioning of the European Union] article 191, paragraph 2</ref>}}

After the adoption of the European Commission's communication on the precautionary principle, the principle has come to inform much EU policy, including areas beyond [[environmental policy]]. As of 2006 it had been integrated into EU laws "in matters such as general product safety, the use of additives for use in animal nutrition, the incineration of waste, and the regulation of genetically modified organisms".<ref name=Recuerda>{{cite journal |author=Recuerda, Miguel A. |title=Risk and Reason in the European Union Law |journal=European Food and Feed Law Review |volume=5 |year=2006 }}</ref>{{rp|282–83}} Through its application in [[case law]], it has become a "general principle of EU law".<ref name=Recuerda/>{{rp|283}}

In Case T-74/00 ''Artegodan'',<ref>{{cite web|url=http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:62000TJ0074|title=EUR-Lex - 62000TJ0074 - EN - EUR-Lex|website=eur-lex.europa.eu}}</ref> the [[General Court (European Union)|General Court]] (then Court of First Instance) appeared willing to extrapolate from the limited provision for the precautionary principle in [[environmental policy]] in article 191(2) [[TFEU]]<ref>{{cite web|url=http://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX:12008E191|title=EUR-Lex - 12008E191 - EN - EUR-Lex|website=eur-lex.europa.eu}}</ref> to a general principle of EU law.<ref>{{Cite book| last1 = Craig| first1 = Paul| last2=de Búrca|first2 = Gráinne |title = EU law: text, cases, and materials| publisher = Oxford University Press| edition = sixth| year = 2015| pages = 112–113 | isbn = 978-0-19-871492-7}}</ref>

==== France ====

In France, the [[Charter for the Environment]] contains a formulation of the precautionary principle (article 5):
{{Blockquote|When the occurrence of any damage, albeit unpredictable in the current state of scientific knowledge, may seriously and irreversibly harm the environment, public authorities shall, with due respect for the principle of precaution and the areas within their jurisdiction, ensure the implementation of procedures for risk assessment and the adoption of temporary measures commensurate with the risk involved in order to preclude the occurrence of such damage.<ref>[http://www.conseil-constitutionnel.fr/conseil-constitutionnel/root/bank_mm/anglais/charter_environnement.pdf ''Charter for the Environment''], [[Constitutional Council (France)|Constitutional Council]] (page visited on 28 August 2016).</ref>}}

====United States====
On 18 July 2005, the City of San Francisco passed a precautionary principle purchasing ordinance,<ref>[http://www.municode.com/Resources/gateway.asp?pid=14134&sid=5 Municode] {{webarchive |url=https://web.archive.org/web/20081205100244/http://www.municode.com/Resources/gateway.asp?pid=14134&sid=5 |date=5 December 2008 }}</ref> which requires the city to weigh the environmental and health costs of its $600&nbsp;million in annual purchases – for everything from cleaning supplies to computers. Members of the Bay Area Working Group on the Precautionary Principle contributed to drafting the Ordinance.

====Australia====
The most important Australian court case so far, due to its exceptionally detailed consideration of the precautionary principle, is Telstra Corporation Limited v Hornsby Shire Council.<ref>[2006] NSWLEC 133 (24 March 2006) [http://www.austlii.edu.au/au/cases/nsw/NSWLEC/2006/133.html].</ref>

The principle was summarised by reference to the [[New South Wales|NSW]] ''Protection of the Environment Administration Act 1991'', which itself provides a good definition of the principle:<ref>{{Cite web|url=http://www.austlii.edu.au/au/legis/nsw/consol_act/poteaa1991485/s6.html|title=PROTECTION OF THE ENVIRONMENT ADMINISTRATION ACT 1991 - SECT 6 Objectives of the Authority|website=austlii.edu.au|access-date=2017-04-03}}</ref>

"If there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reasoning for postponing measures to prevent environmental degradation. In the application of the principle... decisions should be guided by:
(i) careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment; and
(ii) an assessment of risk-weighted consequence of various options".

The most significant points of Justice Preston's decision are the following findings:<ref>Hon. Justice Brian J Preston, (2006), 'Telstra Corporation Limited v Hornsby Shire Council [2006] NSWLEC 133', ''Land and Environment Court of New South Wales''. Paragraphs 125-183. https://www.caselaw.nsw.gov.au/decision/549f8a6b3004262463ad5606</ref>
* The principle and accompanying need to take precautionary measures is "triggered" when two prior conditions exist: a threat of serious or irreversible damage, and scientific uncertainty as to the extent of possible damage.
* Once both are satisfied, "a proportionate precautionary measure may be taken to avert the anticipated threat of environmental damage, but it should be proportionate."
* The threat of serious or irreversible damage should invoke consideration of five factors: the scale of threat (local, regional etc.); the perceived value of the threatened environment; whether the possible impacts are manageable; the level of public concern, and whether there is a rational or scientific basis for the concern.
* The consideration of the level of scientific uncertainty should involve factors which may include: what would constitute sufficient evidence; the level and kind of uncertainty; and the potential to reduce uncertainty.
* The principle shifts the burden of proof. If the principle applies, the burden shifts: "a decision maker must assume the threat of serious or irreversible environmental damage is... a reality [and] the burden of showing this threat... is negligible reverts to the proponent..."
* The precautionary principle invokes preventative action: "the principle permits the taking of preventative measures without having to wait until the reality and seriousness of the threat become fully known".
* "The precautionary principle should not be used to try to avoid all risks."
* The precautionary measures appropriate will depend on the combined effect of "the degree of seriousness and irreversibility of the threat and the degree of uncertainty... the more significant and uncertain the threat, the greater...the precaution required". "...measures should be adopted... proportionate to the potential threats".

====Philippines====
A petition filed 17 May 2013 by environmental group Greenpeace Southeast Asia and farmer-scientist coalition Masipag (''Magsasaka at Siyentipiko sa Pagpapaunlad ng Agrikultura'') asked the appellate court to stop the planting of Bt eggplant in test fields, saying the impacts of such an undertaking to the environment, native crops and human health are still unknown. The Court of Appeals granted the petition, citing the precautionary principle stating "when human activities may lead to threats of serious and irreversible damage to the environment that is scientifically plausible but uncertain, actions shall be taken to avoid or diminish the threat."<ref>{{cite web |url=http://ca.judiciary.gov.ph/cardis/SP00013.pdf |archive-url=https://web.archive.org/web/20160118151419/http://ca.judiciary.gov.ph/cardis/SP00013.pdf |url-status=dead |archive-date=18 January 2016 |title=Greenpeace Southeast Asia (Philippines), et. al. vs. Environmental Management Bureau of the Department of Environment and Natural Resources, et. al. |publisher=Republic of the Philippines Court of Appeals |location=Manila |date=17 May 2013 |access-date=12 March 2016 }}</ref>
Respondents filed a motion for reconsideration in June 2013 and on 20 September 2013 the Court of Appeals chose to uphold their May decision saying the ''bt talong'' field trials violate the people's constitutional right to a "balanced and healthful ecology."<ref>{{cite web |url=http://edigest.elaw.org/sites/default/files/ph.greenpeacese.pdf |title=Greenpeace Southeast Asia (Philippines), et. al. vs. Environment Management Bureau of the Department of Environment and Natural Resources, et. al. |publisher=Republic of the Philippines Court of Appeals |location=Manila |date=17 May 2013 |access-date=12 March 2016 |via=[[Environmental Law Alliance Worldwide|ELAW]] |archive-url=https://web.archive.org/web/20160304105033/http://edigest.elaw.org/sites/default/files/ph.greenpeacese.pdf |archive-date=4 March 2016 |url-status=dead}}</ref><ref>{{cite web |url=http://edigest.elaw.org/sites/default/files/ph.eggplantsept2014.pdf |title=Greenpeace Southeast Asia (Philippines), et. al. vs. Environment Management Bureau of the Department of Environment and Natural Resources, et. al. |publisher=Republic of the Philippines Court of Appeals |location=Manila |date=20 September 2013 |access-date=12 March 2016 |via=ELAW |archive-url=https://web.archive.org/web/20160304084714/http://edigest.elaw.org/sites/default/files/ph.eggplantsept2014.pdf |archive-date=4 March 2016 |url-status=dead}}</ref> The Supreme Court on 8 December 2015 permanently stopped the field testing for Bt (Bacillus thuringiensis) talong (eggplant), upholding the decision of the Court of Appeals which stopped the field trials for the genetically modified eggplant.<ref>{{cite press release|url=http://m.greenpeace.org/international/en/high/press/releases/Philippines-Supreme-Court-bans-development-of-genetically-engineered-products-/ |title=Philippines' Supreme Court bans development of genetically engineered products |publisher=Greenpeace International |date=11 December 2015 |archive-url=https://web.archive.org/web/20151222131524/http://m.greenpeace.org/international/en/high/press/releases/Philippines-Supreme-Court-bans-development-of-genetically-engineered-products-/ |archive-date=22 December 2015}}</ref> The court is the first in the world to adopt the precautionary principle regarding GMO products in its decision. The Supreme Court decision was later reversed following an appeal by researchers at the University of the Philippines Los Baños.<ref>{{cite web|url=https://opinion.inquirer.net/96038/boost-for-bt-talong|title=Boost for Bt 'talong'|publisher=inquirer.net |date=July 2016 |access-date=19 July 2020}}</ref>

==== Corporate ====
[[Body Shop|Body Shop International]], a UK-based cosmetics company, included the precautionary principle in their 2006 chemicals strategy.<ref>{{cite web|url=http://www.thebodyshopinternational.com/NR/rdonlyres/D7F2A9D1-416A-47B8-8BC3-1E858A37F81C/0/BSI_Chemicals_Strategy.pdf |title=Chemicals Strategy |publisher=The Body Shop |date=August 2006 |access-date=12 March 2016}}</ref>

=== Environment and health ===
Fields typically concerned by the precautionary principle are the possibility of:
* [[Global warming]] or [[abrupt climate change]] in general
* [[Extinction]] of species
* Introduction of new products into the environment, with potential impact on [[biodiversity]] (e.g., [[genetically modified organisms]])
* Threats to [[public health]], due to new diseases and techniques (e.g., HIV transmitted through blood transfusion)
* Long-term effects of new technologies (e.g. [[Mobile phone radiation and health|health concerns regarding radiation from cell phones]] and other electronics communications devices)
* Persistent or acute pollution (e.g., [[asbestos]], [[endocrine disruptors]])
* Food safety (e.g., [[Creutzfeldt–Jakob disease]])
* Other new [[biosafety]] issues (e.g., [[artificial life]], new [[molecule]]s)

The precautionary principle is often applied to [[biology|biological]] fields because changes cannot be easily [[containment|contained]] and have the potential of being global. The principle has less relevance to contained fields such as [[aeronautics]], where the few people undergoing [[risk]] have given [[informed consent]] (e.g., a [[test pilot]]). In the case of technological innovation, containment of impact tends to be more difficult if that technology can self-replicate. [[Bill Joy]] emphasised the dangers of replicating genetic technology, nanotechnology, and robotic technology in his article in ''[[Wired (magazine)|Wired]]'', "[[Why the future doesn't need us]]", though he does not specifically cite the precautionary principle. The application of the principle can be seen in the public policy of requiring [[pharmaceutical industry|pharmaceutical companies]] to carry out [[clinical trial]]s to show that new [[medications]] are safe.

Oxford based philosopher [[Nick Bostrom]] discusses the idea of a future powerful [[superintelligence]], and the risks should it attempt to gain atomic level control of matter.<ref>[[Nick Bostrom]] 2003 Ethical Issues in Advanced Artificial Intelligence – section 2</ref>

Application of the principle modifies the status of innovation and [[risk assessment]]: it is not the risk that must be avoided or amended, but a potential risk that must be prevented. Thus, in the case of regulation of scientific research, there is a third party beyond the scientist and the regulator: the consumer.

In an analysis concerning application of the precautionary principle to [[nanotechnology]], Chris Phoenix and Mike Treder posit that there are ''two forms'' of the principle, which they call the "strict form" and the "active form".<ref>{{cite web|url=http://www.crnano.org/precautionary.htm |title=Nanotechnology: Precautionary Principle Analyzed |publisher=Center for Responsible Nanotechnology |date=January 2004 |access-date=12 March 2016}}</ref> The former "requires inaction when action might pose a risk", while the latter means "choosing less risky alternatives when they are available, and [...] taking responsibility for potential risks." [[Thomas Alured Faunce]] has argued for stronger application of the precautionary principle by chemical and health technology regulators particularly in relation to Ti0<sub>2</sub> and ZnO [[nanoparticle]]s in [[sunscreens]], biocidal nanosilver in waterways and products whose manufacture, handling or recycling exposes humans to the risk of inhaling multi-walled carbon nanotubes.<ref>{{cite journal  |vauthors=Faunce TA, etal |title=Sunscreen Safety: The Precautionary Principle, The Australian Therapeutic Goods Administration and Nanoparticles in Sunscreens |journal=Nanoethics |volume=2 |issue= 3|pages=231–240 |year=2008 |doi=10.1007/s11569-008-0041-z |s2cid=55719697 |url=http://law.anu.edu.au/StaffUploads/236-Nanoethics%20Sunscreens%202008.pdf |archive-url=https://web.archive.org/web/20110228183131/http://law.anu.edu.au/StaffUploads/236-Nanoethics%20Sunscreens%202008.pdf |archive-date=28 February 2011}}</ref>

=== Animal sentience precautionary principle ===
{{See also|Ethics of uncertain sentience}}

Appeals to the precautionary principle have often characterized the debates concerning animal sentience – that is, the question of whether animals are able to feel "subjective experiences with an attractive or aversive quality",<ref name=":0">{{Cite journal|last=Birch|first=Jonathan|author-link=Jonathan Birch (philosopher)|date=2017|title=Animal sentience and the precautionary principle|url=http://eprints.lse.ac.uk/84099/1/Birch_%20Animal%20sentience%20and%20the.pdf|journal=Animal Sentience|volume=16|issue=1}}</ref> such as pain, pleasure, happiness, or joy – in relation to the question of whether we should legally protect sentient animals. A version of the precautionary principle suitable for the problem of animal sentience has been proposed by [[London School of Economics|LSE]] philosopher [[Jonathan Birch (philosopher)|Jonathan Birch]]: "The idea is that when the evidence of sentience is inconclusive, we should 'give the animal the benefit of doubt' or 'err on the side of caution' in formulating animal protection legislation."<ref name=":0" /> Since we cannot reach absolute certainty with regards to the fact that some animals are sentient, the precautionary principle has been invoked in order to grant potentially sentient animals "basic legal protections".<ref name=":0" /> Birch's formulation of the animal sentience precautionary principle runs as follows:{{blockquote|Where there are threats of serious, negative animal welfare outcomes, lack of full scientific certainty as to the sentience of the animals in question shall not be used as a reason for postponing cost-effective measures to prevent those outcomes.<ref name=":0" />}}This version of the precautionary principle consists of an epistemic and a decision rule. The former concerns the "evidential bar" that should be required for animal sentience. In other words, how much evidence of sentience is necessary before one decides to apply precautionary measures? According to Birch, only ''some'' evidence would be sufficient, which means that the evidential bar should be set at low levels. Birch proposes to consider the evidence that certain animals are sentient sufficient whenever "statistically significant evidence ... of the presence of at least one credible indicator of sentience in at least one species of that order" has been obtained.<ref name=":0" /> For practical reasons, Birch says, the evidence of sentience should concern the [[Order (biology)|order]], so that if one [[species]] meets the conditions of sentience, then all the species of the same order should be considered sentient and should be thus legally protected. This is due to the fact that, on the one hand, "to investigate sentience separately in different orders" is feasible,<ref name=":0" /> whereas on the other hand, since some orders include thousands of species, it would be unfeasible to study their sentience separately.

What is more, the evidential bar should be so low that only ''one'' indicator of sentience in the species of a specific order will be sufficient in order for the precautionary principle to be applied. Such indicator should be "an observable phenomenon that experiments can be designed to detect, and it must be credible that the presence of this indicator is explained by sentience".<ref name="Birch 1–16">{{Cite journal|last=Birch|first=Jonathan|title=Animal sentience and the precautionary principle|journal=Animal Sentience|pages=1–16}}</ref> Lists of such criteria already exist for detecting animal pain. The aim is to create analogous lists for other criteria of sentience, such as happiness, fear, or joy. The presence of one of these criteria should be demonstrated by means of experiments which must meet "the normal scientific standards".<ref name=":0" />

Regarding the second part of the animal sentience precautionary principle, the decision rule concerns the requirement that we have to act once there is sufficient evidence of a seriously bad outcome. According to Birch, "we should aim to include within the scope of animal protection legislation all animals for which the evidence of sentience is sufficient, according to the standard of sufficiency outlined [above]".<ref name="Birch 1–16"/> In other words, the decision rule states that once the aforementioned low evidential bar is met, then we ''should'' act in a precautionary way.<ref name=":0" /> Birch's proposal also "deliberately leaves open the question of how, and to what extent, the treatment of these animals should be regulated", thus also leaving open the content of the regulations, as this will largely depend on the animal in question.<ref name=":0" />